1. Field of the Invention
This invention pertains to the fields of ballistics, optics, and electronics. More particularly, this invention relates to the field of propellant evaluation. In still greater particularity, this invention pertains to a device for measuring pressure-travel relationships in a gun system.
2. Description of the Prior art
In order to more fully understood combustion kinetics in gun systems, there is a need to obtain data on relationships between chamber pressure and projectile position. Various methods have been employed to determine certain of the projectile travel data, such as projectile velocity upon exit from the barrel, but there is a long felt need for a device to accurately measure projectile positions and corresponding chamber pressures. Devices have been used to determine the moment that the projectile passes the muzzle, which devices have been triggered by the radiation from gases behind the projectile as it passes the muzzle. Such a device is illustrated in U.S. Pat. No. 3,453,882 granted to Richard D. Kirkendall on 8 July 1969. Yet another device utilizes light reflected from a source on the projectile itself to measure acceleration. Still another method measures barrel velocity by directing light through the barrel and recording images on film. This latter device is illustrated by U.S. Pat. No. 3,019,073 granted to Donald A. Hall on 21 Jan. 1959.
While all of the above devices are satisfactory for their intended purposes, a reliable means for measuring the exact projectile position and relating this position to chamber pressure is needed.